The purpose of this project is to develop reliable and valid measures of impairment, activities, and participation for use in clinical practice and research. Existing instruments that measure these aspects of disablement are collected routinely in a variety of settings, but have not been evaluated rigorously with contemporary measurement methodology. Existing information from the Model Spinal Cord Injury (SCI) Systems national database will be used to evaluate the measurement characteristics of several instruments, increase our understanding of the recovery process, and improve the clinical utility of this information. The aims of this methodologic project are to: (1) evaluate the quality of measures that can be derived from a national database, and (2) produce accurate and precise outcome measures that can be used in subsequent research in which hypotheses can be appropriately tested. The research activities will consist of a series of secondary analyses of data for existing instruments that will address the shortcomings of composite raw scores through the use of state-of-the-art measurement methodology. Data for approximately 5000 cases collected by 18 Model SCI Systems sites will be used for the instrument calibration. Instruments measuring the original components of the World Health Organization model (impairment, disability and handicap) are included in the Model SCI System database. Records from the database will be stripped of patient identifiers and, when transferred to the applicant, will be reformatted into ASCII files in preparation for analyses. The Rasch measurement model will be applied in the proposed analysis (Rasch, 1960) using rating scale analysis (Wright & Masters, 1982) conducted with WINSTEPS (Linacre & Wright, 2000), a Rasch computer program. Completion of the project will provide fine-tuned measures for use in clinical trials and practice.